Lead-Free Cs2TeX6 (X = Cl, Br, and I) Perovskite Microcrystals with High Stability for Efficient Photocatalytic CO2 Reduction

In response to calling for a sustainable and carbon-neutral economy, the conversion of CO₂ to useful chemicals using the solar energy is a potential tactic to relieve the global energy dilemma and environmental issues, which has been a hot topic so far. Recently, the lead halide perovskites as novel photocatalysts have attracted researchers' interests. However, they generally encounter poor stability and lead toxicity, restricting their large-scale practical applications. Here, the lead-free Cs₂TeX₆ (X = Cl, Cl_0.5Br_0.5, Br, Br_0.5I_0.5, and I) perovskite microcrystals with strong stability were prepared and used to realize the CO₂ photocatalytic reduction efficiently. The prepared Cs₂TeBr₆ microcrystals delivered stronger photocatalytic ability than many previously reported photocatalysts, with the CO and CH₄ yields of 308.63 and 60.42 μmolg^-1, respectively, under 3 h of illumination. The presented strategy in our work provides new ideas of designing and preparing efficient and practical CO₂ reduction photocatalysts based on nonleaded and high-stability halide perovskites.